1. Technical Field
Embodiments of this disclosure relate to an image forming apparatus, and more specifically to an image forming apparatus including a recording head for discharging liquid droplets and a head tank for supplying liquid to the recording head.
2. Description of the Related Art
Image forming apparatuses are used as printers, facsimile machines, copiers, plotters, or multifunction peripherals having two or more of the foregoing capabilities. As one type of image forming apparatus employing a liquid discharge recording method, inkjet recording apparatuses are known that use a recording head (liquid discharge head or droplet discharge head) for discharging droplets of ink or other liquid.
To replenish and supply liquid from a main tank to a head tank (also referred to as “sub tank”) mounted on the recording head even during printing operation, such an image forming apparatus may have a displacement member (hereinafter also referred to as “feeler”) mounted on the head tank and displaceable with the remaining amount of liquid in the head tank, a first sensor (carriage-side detector) mounted on a carriage to detect that the displacement member is at a predetermined first position, and a second sensor (body-side detector) mounted on an apparatus body to detect that the displacement member is at a predetermined second position. The image forming apparatus detects and stores a differential supply amount corresponding to a displacement amount of the displacement member between the first position and the second position. In supplying liquid from the main tank to the head tank without using the second sensor on the apparatus body, the image forming apparatus supplies liquid to the head tank by the differential supply amount after detection of the displacement member with the first sensor.